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| Mirrors > Home > ILE Home > Th. List > rexbidv | GIF version | ||
| Description: Formula-building rule for restricted existential quantifier (deduction form). (Contributed by NM, 20-Nov-1994.) |
| Ref | Expression |
|---|---|
| ralbidv.1 | ⊢ (𝜑 → (𝜓 ↔ 𝜒)) |
| Ref | Expression |
|---|---|
| rexbidv | ⊢ (𝜑 → (∃𝑥 ∈ 𝐴 𝜓 ↔ ∃𝑥 ∈ 𝐴 𝜒)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nfv 1542 | . 2 ⊢ Ⅎ𝑥𝜑 | |
| 2 | ralbidv.1 | . 2 ⊢ (𝜑 → (𝜓 ↔ 𝜒)) | |
| 3 | 1, 2 | rexbid 2496 | 1 ⊢ (𝜑 → (∃𝑥 ∈ 𝐴 𝜓 ↔ ∃𝑥 ∈ 𝐴 𝜒)) |
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